Author interview: UNIX and Linux System Administration Handbook

Ben: I wear a bunch of different hats as an engineer at AppliedTrust in Boulder. In addition to consulting on architecture and operations in UNIX and Linux environments, I think a lot about next generation technologies. Virtualization (in its myriad forms), application security, and the adoption of open source are all of interest. I also have a interest in the history of computing generally, and of UNIX and Linux in particular. Outside of computing, I enjoy the republic of Boulder as much as possible.

Garth: I was one of the original authors of the UNIX book lo these many years ago, but I've spent time on a variety of projects since then. Over time, I've actually done more software development than administration.

Evi: I'm Evi Nemeth, former Computer Science faculty at the University of Colorado. I'm now out of the UNIX/Linux/CS world altogether; I retired, bought a sailboat, took off and am currently in French Polynesia, half way across the Pacific en route to New Zealand. I'm working on making my boat single-hander-friendly for when I run out of crew. I do have email on the boat via my ham radio; it's like uucp at about 100 characters per minute.

Trent: I'm a scientist at heart, and I love understanding all the layers of a system. When I'm not writing, I'm deep in the trenches working on IT infrastructure issues that range from low-level technical issues to policy and management.

Ben: We anticipate a mid to late July shelf date. There is loads of new material in this combined UNIX and Linux edition, including new chapters on virtualization, scripting, and green IT practices. I'm very pleased with the new set of cartoons and cover art. Also, I'm thrilled to be included as a new author after contributing to the 2nd edition of the Linux book.

Garth: Many of the existing chapters have had near-complete rewrites as well. You might think that long-standing, basic technologies like disk storage and email would be relatively stable, but that's not true at all. The way that most sites manage these resources has changed completely just in the last five years or so.

Evi: LAH and USAH have merged back together. It's due out sometime soon (July 2010). I'm most excited that it's finally done; I left the boat in Panama and came back to Colorado for a year to work full time on the book — it's a huge amount of work.

Trent: It better be in bookstores in the next 2 weeks!! I'm super excited about the new Green IT section — it presents opportunities for sysadmins to make a huge difference to our planet.

Ben: Linux is recognized as an enterprise-grade operating system that has proven its capabilities throughout the explosion of computing in the last twenty years. It has significant momentum behind it, much more so than other leading UNIX variants. One could argue that UNIX lives on but looks to Linux as its leader. It has enough in common with traditional UNIX that it make sense to cover it all in one place.

Garth: One factor that's helped make it possible to reintegrate is the dramatic shakeout in the UNIX market. There simply aren't as many major versions of Unix around as there were ten years ago. We've seen a similar consolidation in the Linux arena as well, with most activity consolidating around a few major distributions.

Evi: Personally, I'm not sure we should ever have separated UNIX and Linux into 2 books. We thought that conditional text (if Linux, blah, blah, else ...) would make it easy to manage both books with minimal effort. Not true. We also feel that this is probably the last edition that will be on paper and maybe the last edition period, so if we are doing one last book, let's cover all the systems we can. I'm sorry we didn't manage to include MacOS too.

Trent: Combining the books makes sense because system administrators manage both UNIX and Linux systems ... organizations shouldn't be separating duties for these platforms since they're so similar.

Evi: I think the fact that Linux ran on PCs instead of the special vendor specific hardware of most UNIX systems gave Linux a leg up. University students ran Linux on their PCs, graduated, and went to work in corporate America (Europe, etc.). Linux also embraced (or tolerated) Windows more than the UNIX vendors and found ways for the systems to co-exist peacefully.

Trent: The community. It's a lot easier to support Linux these days because if there's any issue, there are hundreds or thousands of people to turn to on the 'net for help. It's a lot easier than sitting on hold with a vendor's call center for hours.

Ben: In the near term I believe that UNIX environments will continue as they have, serving as venerable, tenured systems with proven stability and some powerful capabilities. Most of the UNIX systems I work with run heavy databases or specific enterprise applications. OpenSolaris is an impressive system with advanced features that don't exist elsewhere. In the longer term, it seems to me that Linux will displace UNIX. All the major vendors contribute to Linux's development (as LWN's own data suggests) and even promote standardization.

Garth: Traditional Unix vendors don't have the resources to compete against Linux on every front, so they've had to pick their battles and concentrate on distinguishing themselves through enterprise features such as database or filesystem performance. However, the number of domains in which it's possible to demonstrate a proprietary advantage over Linux is continuously shrinking. I don't see any reason for the current trends to change, so I'm pessimistic about the future of traditional Unix.

Evi: UNIXes that run on PC hardware will survive in niches — FreeBSD in embedded systems, OpenBSD in security conscious spots, Open Solaris if Oracle leaves it alone, etc., but systems on proprietary hardware (AIX, HP-UX, Solaris) will continue to decline in market share. Note that each of these three vendors is hedging their bets with a Linux product or with a Linux that runs on their hardware.

Trent: There's such a large installed base that I think Unix is going to be around for a very long, long time. But, I can tell you that almost all the new infrastructure I build is on Linux.

Ben: I was introduced to Linux before UNIX, and I suspect that I wouldn't be on the same path that I'm on today without it. In fact, I grew up from adolescence using Linux and today I look at closed systems as a broken, legacy model of development. I love the creativity and community that open systems offer. To me it's a great thing that has kept UNIX alive.

Garth: In some ways, this is like asking, "The rise of humanity: good or bad?" Linux has warts, but so do the alternatives. It's not the solution so much as the context in which other things happen.

Outside of a thousand minor differences, there really isn't a dime's worth of difference between the various Unix-like operating systems. They are all basically the same. (Well, except perhaps for AIX. Whatever else one might say about it, it's definitely not the same.) Fundamental, game-changing advances — such as Solaris's ZFS filesystem — are few and far between.

Evi: Yes, the success of Linux is a very good thing. Each open source "Unix" has strengths. Linux is quick to see a cool idea in another system, re-engineer it, and voila, it's part of Linux too.

Trent: Linux is great!! In a way, Linux is really UNIX for the people. We needed that. It's forced the entire industry to be more open, which I'm not sure a more established open-source UNIX would have achieved because it's inspired a shift in mindset.

Ben: Settle on a few more standards, such as log formats, command line arguments, configuration file syntax, and extensibility. As always, the more documentation, the better. Active communities where developers and users interact are extremely valuable.

Garth: Unix and Linux developers have traditionally designed software to be as flexible and configurable as possible. A good example of this approach is the original sendmail, which knew practically nothing about email addressing or transport until you manually programmed that knowledge into its configuration file. Many common systems still take that general approach: here's the tool kit, build whatever you like. Have fun!

This approach has its advantages, but it also imposes a cognitive burden on everyone downstream of the developers. I'd like to see more focus on simplicity and predictability in Linux distributions and less concern about hypothetical scenarios and edge cases. A Linux server may be a lot more complicated than an iPhone, but it surely doesn't need to be 1000 times more complicated, as it currently is.

Unfortunately, it's especially hard to promote simplicity and clarity in the open source world. It's easy to accept patches that add incremental features but hard to remove anything or break compatibility. Reaching design consensus on future developments is hard enough without revisiting the messes of the past.

Evi: Standardize! Make command names, arguments, and behavior the same. Get rid of the not-invented-here attitude.

Trent: Keep it simple. The early success of both UNIX and Linux can be attributed to their simple, modular approach. Too often these days folks are developing packages that are like a giant corn maze (but I won't name any names!). We'll all get farther if the development community is focused on simplicity and modularity.

Garth: The Linux community has put a lot of effort into strip-mining the UNIX systems of the past and digging out the nuggets of value that weren't nailed down. So no, I don't think administrators unfamiliar with traditional UNIX systems are missing too much. On the other hand, we do seem to be stuck in about 1990 with respect to our basic idea of what an operating system should be. Look at all the incredible developments we've seen over the last 20 years in application and web development; software is completely different now. I hope the triumph of UNIX and Linux don't lock us into the POSIX API indefinitely.

Evi: This generation of Linuxites have used UNIX, Linux is a UNIX system. It has commands that you type to a shell instead of driving thru a zillion menus, it has all the important concepts of UNIX, like pipes and input output redirection, it has man pages, ...

Trent: Process adherence. In the UNIX world of yesterday, we had giant machines that filled an entire room, and dozens or hundreds of users shared them. In order to achieve a reasonable service level, system administrators had to be very process-focused, else they would impact many users if a mistake occurred. Today, a single user may have dozens of systems, physical and virtual. System administrators still need to have a well-developed, well-followed set of processes to maintain them to provide an even higher level of service.

Ben: The cloud is clearly the direction that is currently leading the pack, and I'm anxious to see what happens next in the space. I hope that open source development continues to thrive. It will also be interesting to see what happens with security. People are paying a lot of attention to it these days, and we're well positioned to fix the less secure, trust-based models of earlier systems.

Evi: A fundamental principle of UNIX-ish operating systems is that they provide commands that do one thing well and then the plumbing to hook them together to get a final result. Windows-ish operating systems try to think of everything a user might want to do and make a command or option for it. If the Windows developer didn't think of the thing you need to do, you are out of luck. Next generation operating systems need the UNIXy approach. Keep things simple, take small steps, but do it well.

Trent: I hope they build operating systems that perform well. Back in the day, we had to optimize for every last cycle, because cycles were few. Some new OS developers have had the luxury of hardware being abstracted from them, and it's easy to forget what really happens at that layer. It's easy to fall into a pattern of slapping layer upon layer, resulting in a lot of kernel and application bloat. Keep it simple, and think about how to optimize for performance.

Ben: I'm a lurker on LWN and I've learned a lot from both the articles and the comments. I appreciate the active open source community on the site. Thanks for reading.

Garth: I'm excited about Btrfs and really looking forward to its debut as a production system. Check it out!

Evi: I need crew. Is there anyone out there (between jobs maybe) who isn't busy between September and November 2010? We share expenses on consumables; I pay for boat maintenance.

Trent: I hope in UNIX and Linux System Administration Handbook (4th Edition) we teach folks how to be good system administrators and find answers on their own, rather than providing every possible answer for them. System administrators need knowledge acquisition and problem solving skills more than anything.